The present invention is related to saws, and more particularly, to power driven saws which utilize an endless array of cutting teeth.
The use of chain saws in many applications is not without disadvantages. Compared to carpenter's handsaws and power band saws, the kerf of a chain saw is much wider. The wider kerf is undesirable for two reasons: (1) the wider kerf removes more material from the cut than a narrower kerf would and thus, converts a larger portion of the material being cut to waste, and (2) removal of more material from the cut requires more power input for cutting.
Saws, such as a hand saw or those employing reciprocating saw blade mechanisms, have the disadvantage of inefficiency associated with the return stroke.
The band saw has the advantage over the reciprocating saw in that return stroke efficiency is eliminated as the band saw operates to continuously cut. Further, the band saw has a much narrower kerf as compared to the chain saw. However, the use of a band saw also has disadvantages. First, the band saw has a throat limitation which limits the size of the material being cut. And, of course, the throat limitation of a band saw limits the effectiveness of the band saw if it were to be used in some portable embodiment. Secondly, a band saw blade is constantly undergoing bending and flexing as it is engaged by the drive and idler wheels. Since the band saw blade must be able to withstand the flexing and bending, the blade is limited to certain suitable flexible materials and to suitable hardness tempers.
The saw of the present invention substantially mitigates or eliminates the disadvantages associated with the other types of currently employed saw devices and incorporates many of the desirable features of the chain saw and band saws.